# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import logging

from packaging import version

from reno import loader

LOG = logging.getLogger(__name__)


def compute_next_version(conf):
    "Compute the next semantic version based on the available release notes."
    LOG.debug('starting semver-next')
    ldr = loader.Loader(conf, ignore_cache=True)
    LOG.debug('known versions: %s', ldr.versions)

    # We want to include any notes in the local working directory or
    # in any commits that came after the last tag. We should never end
    # up with more than 2 entries in to_include.
    to_include = []
    for to_consider in ldr.versions:
        if to_consider == '*working-copy*':
            to_include.append(to_consider)
            continue
        # This check relies on PEP 440 versioning
        parsed = version.Version(to_consider)
        if parsed.post:
            to_include.append(to_consider)
            continue
        break

    # If we found no commits then we're sitting on a real tag and
    # there is nothing to do to update the version.
    if not to_include:
        LOG.debug('found no staged notes and no post-release commits')
        return ldr.versions[0]

    LOG.debug('including notes from %s', to_include)

    candidate_bases = to_include[:]
    if candidate_bases[0] == '*working-copy*':
        candidate_bases = candidate_bases[1:]

    if not candidate_bases:
        # We have a real tag and some locally modified files. Use the
        # real tag as the basis of the next version.
        base_version = version.Version(ldr.versions[1])
    else:
        base_version = version.Version(candidate_bases[0])

    LOG.debug('base version %s', base_version)

    inc_minor = False
    inc_patch = False
    for ver in to_include:
        for filename, sha in ldr[ver]:
            notes = ldr.parse_note_file(filename, sha)
            for section in conf.semver_major:
                if notes.get(section, []):
                    LOG.debug('found breaking change in %r section of %s',
                              section, filename)
                    return '{}.0.0'.format(base_version.major + 1)
            for section in conf.semver_minor:
                if notes.get(section, []):
                    LOG.debug('found feature in %r section of %s',
                              section, filename)
                    inc_minor = True
                    break
            for section in conf.semver_patch:
                if notes.get(section, []):
                    LOG.debug('found bugfix in %r section of %s',
                              section, filename)
                    inc_patch = True
                    break

    major = base_version.major
    minor = base_version.minor
    patch = base_version.micro
    if inc_patch:
        patch += 1
    if inc_minor:
        minor += 1
        patch = 0
    return '{}.{}.{}'.format(major, minor, patch)


def semver_next_cmd(args, conf):
    "Calculate next semantic version number"
    print(compute_next_version(conf))
    return 0
